Automatic tapping-head



H. SPENCE. AUTOMATIC TAPPING HEAD.

APPLICATION FILED JULY 24,1918. 1,327,497, I Patented Jan. 6,1920.

Y I 2 SHEETS-SHEET I- WITNESSES IIVVE/VTOH I A enr Spence l y I By W I Arm/Mk8 H. SPENCE.

AUTOMATIC TAPPING HEAD.

APPLICATION FILED JULY 24, I918.

Patented Jan. 6, 1920.

2 SHEETS-SHEET 2 J ,4,

fax/6% INVENTOI? Henry Spence BY mo/mm HENRY SPENCE, OF KEARNEY, NEW JERSEY.

AUTOMATIC TAPPING-HEAD.

Specification of Letters Patent.

Patented Jan. 6, 1920.

Application filed July 24, 1918. Serial No. 246,555.

To all whom it may concern:

Be it known that I, HENRY SrENoE, a subject of the King of Great Britain, and a resident of Kearney, in the county of Hudson and State of New Jersey, have invented a new and Improved Automatic Tapping- Head, of which the following is a full, clear, and exact description.

This invention relates to metal working tools, and has particular reference to means for automatically controlling the operation of taps or the like.

Among the objects of the invention is to provide a head or attachment for a drill press with means within or associated there with for operating the tap in a forward or positive direction at a low speed, and for returning it after the hole has been tapped at high speed.

Another object of the invention is to provide a tapping head with means for operating the tap in a forward direction to a predetermined distance and then automatically withdrawing the same from the tapped hole.

Another object of the invention is to provide a tapping head with means contained therein to operate the tapping tool forward, means being provided to determine the extent of such forward movement, and then automatically return or withdraw the tapping tool at quick speed.

A still further object of the invention is to provide the tapping head with internal reversible and interchangeable gear mechanism so designed as to operate the tapping tool forward for either right or left hand threads and for automatically withdrawing the tapping tool after it has been operated a redetermined distance.

ith the foregoing and other objects in view the invention consists in the arrange ment and combination of parts hereinafter described and claimed, and while the invention is not restricted to the exact details of construction disclosed or suggested herein, still for the purpose of illustrating a practical embodiment thereof reference is had to the accompanying drawings, in which like reference characters designate the same parts in the several views, and in which Figure 1 is a vertical central section on the line'1.1 of Fig. 2.

Fig. 2 is a vertlcal section substantially at right angles to Fig. 1, the section being approximately on the line 2-2 of Fig. 1.

. description may be understoo Figs. 3 and 4 are horizontal sections on the corresponding lines of Fig. 1.

Fig. 5 is a detail in rear elevation showing the indicator and the finger piece of the safety stop; and

Fig. 6 is a detail view partly in section of the safety stop.

Referring now more specifically to the drawings, I show at 10 a chuck or mandrel ofa drill press which for the urpose of this cl to be rotating continuously in the direction indicated by the arrow marked thereon. 11 indicates a coupling or socket member adapted to rotate in the upper end of the casing 12 of my improved tapping head, a nut 13 being employed to hold the socket member from end wise movement in said head end but allowing free relative rotation between the socket member and the head. The tool spindle 14: extending centrally through the head 12 has a reduced upper end projecting into the central bore 15 of the socket member as a bearing, but is free to move up and down therein. 16 indicates the shank of a tapping tool of any well known type. As the parts are adjusted in Figs. 1 and 2'the tool 16 will be understood to be rotating toward the right, or in the same direction as the mandrel 10, at low speed and tapping a hole.

Referring to the device between the man drel and the tapping tool, 17 is a pinion carried by the inner or lower end of the socket member and meshing on the one side with a large gear 18 and on the other side with a gear 19 of about the same diameter as the pinion 17. The gear 18 is journaled in a bearing at 20 and around a shaft 21, said shaft having at its lower end a pinion 22 meshing with a larger gear 28 splined to the spindle 14. The gear 18 carries a beveled gear 24 and adjacent thereto is shown a clutch member 25 with which cooperates a clutch collar 26 splined upon the shaft 21. As shown in Fig. 1 the clutch members 25 and 26 are connected and hence the rotation of the mandrel will be transmitted through the gears '17 and 18, clutch members 25 and 26, shaft 21, and gears 22 and 23 to the spindle 14;. Since the gear 18 is materially larger in diameter than its driving pinion and likewise the driven gear 23 is larger than its driving pinion 22, clutched to rotate at the same angular speed as the gear 18, the spindle and tool carried thereby are being rotated at low. speed.

27 indicates another internal shaft parallel to the axis of the spindle 14 of somewhat the same nature as the shaft 21 and upon which is splined a slidable clutch collar 28. This collar is located between two clutch members 29 and 30 constituting parts respectively of beveled gears 31 and 32, the latter of which is connected to the gear 19. A beveled gear 33 connects the two gears 31 and 32. A gear 34 is fixed to the shaft 27 and meshes constantly with a gear 35 attached to the same sleeve as the gear 23.

With the parts adjusted as shown in Fig. 1 and tapping, the gears 19, 32, 33, and 31 are being operated'idly from the pinion 17, and the gear 34, shaft 27, and clutch collar 28 are being driven idly from the gear When the tool has been operated sufficiently far in a downward direction the clutch collars 26 and 28 will both be shifted simultaneously, the former into its mid position between the clutch member 25 and the clutch member 36, and the latter into engagement with the clutch member 29 looking the gear 31 to the shaft 27. Under these conditions the mandrel 10 and socket member 11 still rotating in the same direction as before, the tool 16 will be rotated in a reverse direction at approximately the same speed as the mandrel through the gears 17 19 32, 33, and 31, clutch members 29 and 28, shaft 27, and gears 34 and 35.

The other gear elements shown in Fig. 1 and not thus far described comprise a beveled; gear 37 to which the clutch member 36 is attached and journaled around the shaft 21, and a beveled gear 38 connecting the two gears 34'and 37. These gears during the two operations thus far described run idlv.

The means as shown to control the position and action of the clutch collars 26 and 28 is a pair of yokes 39 and 40 having arms extending inward and jointed together at 41 alongside of the central spindle, said arms being fulcrumed between the joint 41 and the yokes, one in a bar 42 and the other in a bracket 43. (See Fig. 3.) During the operation of the machine the fulcrum points 42 and 43 are stationary being supported in the casing 12 having fixed elevation and held from rotation by any suitable means such as a bar 44 clamped in a socket 45 and adapted to bear against some fixed object.

The means I provide for the automatic shifting of the clutches and reversal of the direction of the driven member includes the following devices or their'equivalent. As shown in Figs. 2 and 4, 46 and 47 represent a pair of right and left threaded feed screws journaled in bearings at the top and bottom of the casing 12. These screws are provided with threads 'the'piteh "of which is the same as that of'the tapping tool and they-are rotated simultaneously both in the same direction by .any suitable ;means, the

direction depending upon the direction of rotation of the tapping tool. As indicated these screws are connected to gears 48 and 49 respectively of the same size and driven by another gear of the same size located at any convenient place and having the same rotation as the tool spindle so that while the tool spindle is being rotated both of the screws are rotated at the same speed but in opposite directions from the spindle. As shown herein the gears and screws are driven from the gear 23. 50 is an indicator operating in and along a slot 51 formed in the vertical wall of the casing 12. Said indicator is carried by a follower 52 having an internal thread and operated up and down by means of the right handed screw 46. The inner end of the follower arm constitutes a yoke 53 embracing the spindle 14. It will be understood that the downward feed of the spindle incident to the thread of the tap will be synchronous with the downward feed of the follower and indicator. This indicator operates along a scale 54 to which reference is had to determine the position or movement of the tap. The engagement of the yoke 53 with the spindle insures against the possible rotation of the follower. While the screw 46 feeds the .follower 52 downward during the tapping action, the screw 47 rotating in the same direction at such time will cause the upward movement of a pair of spaced stop members 55 and 56 in the nature of followers. These stop members have their inner ends in vertical alinement with the joint 41 of the shifting clutch yokes and are provided with spring cushions 57 which are adapted to abut against said joint and after sufficient compression of the cushions the clutches will be shifted with a snap. These stop members 55 and 56 are guided at their outer ends along a guide rod 58 which holds them from rotation and insuring that the left hand thread of said screw 47 will cause the movement of the stop members in a direction opposite to the direction of movement of the follower 52. In other words the stop members are suitably adjusted upon the screw 47 so as to permit the desired downward movement of the tap and when that point is reached when the tap should be withdrawnthe lower spring 57 will have moved upward against the joint 41 and soon thereafter the tension of the spring will be exerted to throw the clutch arms far enough around their fulcrum points 42 and 43 to throw the clutch collar 26 to its mid position and the clutch collar 28 into mesh with the clutch member 29. The tool spindle will then be reversed as already described and will quickly withdraw the tap from the work, the reverse rotation continuing until the upper spring cushion 57 will have been brought down-into shifting engagement with the upper face of the joint 41 again shifting the clutches to make a positive or forward drive.

Any suitable means may be provided to allow the continuous rotation of the mandrel while the tool spindle remains at rest.

Attention is now called to Figs. 1, 3, and 6 in the illustration of the mounting of the bar 42 constituting the fulcrum for the yoke 39. The inner end of this bar has a pin and slot connection 59 with a fixed support 60, while its outer end has a head 61 journaled in an eccentric bearing 62 having a finger piece 63 on the outside of the casing 12. A spring 64 surrounding the bar maintains a locking pin 65 engaged in one of a series of holes 66 formed in the hub of the eccentric 62. As indicated in Fig. 1 the eccentricity of the eccentric 62 is such as to hold the clutch collar 26 elevated. By suit able design the eccentric may be so arranged as when turned to a mid position both the clutch members may be out of gear, but when the eccentric is rotated a one half turn from the position indicated in Fig. 1 the clutch collars will be reversed so as to operate a left threaded tap, the driving of which will be accomplished through the gears 17, 18, 38 and 37, clutch members 36 and 26, shaft 21, and gears 22 and 23. This will be at a low speed but in a direction reverse to that first described. At the end of this operation the stop member 56 will opcrate downward against the point 41 and will eventually shift the clutches so as to release the collar 26 and throw the clutch collar 28 into mesh with the clutch member 30, when the return operation will be at high speed through the gears 17, 19, and 32, clutch members 30 and 28, shaft 27, and gears 34 and 35. I It will thus be seen that the operator through the manipulation of the finger piece 68 may readily control the operation of the device either to reverse the direction of movement at any time or to maintain complete control thereof. Access may be had when desired to the inside of the casing 12 without disconnecting the parts through a manhole 67 formed in the front of the casing or any other convenient place.

I claim:

1. The herein described automatic tapping head for drill presses comprising a casing, means to support the casing upon the drill press mandrel, means to prevent rotation of the casing, a tool spindle journaled in the casing, and devices within the casing serving to rotate the spindle at low speed in either a clockwise or counterclockwise direction and at high speed in the opposite direction while the press mandrel continues to rotate in the same direction.

2. In a tapping head for drill presses, the combination with a press mandrel op erating continuously in one direction and,

a tapping spindle of gear connections between the press mandrel and the spindle to cause rotation of the spindle at low speed in either a clockwise or counter-clockwise direction, and to automatically reverse such rotation at high speed.

3. In a device of the character set forth, the combination of a driving member adapted to rotate continuously in the same direction, a driven member, said driven member being mounted to rotate in the same direction as the driving member and the reverse and also adapted to move longitudinally of itself, gear connections between the driving and driven members providing for the rotation of the driven member in either a clockwise or counter-clockwise direction, the reversal of said direction, and the return movement of the driven member endwise back toward its starting position.

4. In a device of the class set forth, the combination of a rotary driving member fixed from endwise movement, a driven member rotatably mounted and slidable along its axis, and connections between the driving and driven members providing for the rotation of the driven member in either a right or left direction while the driving member rotates only in one direction, the automatic reversal of the direction of the driven member, and the return of the driven member backward toward its starting position.

5. In a device of the class set forth, the combination with a driving member fixed from endwise movement and rotatable in a constant direction at high speed, of a driven member adapted to rotate in either direction and to move axially, and connec tions between the driving and driven members serving to cause rotation of the driven member at low speed in either a clockwise or counter-clockwise direction while it is moving endwise away from the driving member to automatically stop said endwise movement of the driven member, and to re verse the direction of rotation of the driven member and return thereof toward starting position at high speed.

6. In a tapping head for drill presses, the combination wit-h a driving member of a press held from endwise movement and adapted to rotate constantly in the same direction, of a driven member arranged coaxially of the driving member and movable longitudinally along said aXis away from and toward said driving member, gear connections between the driving and driven members, and means to control said gearing members to provide for the rotation of the driven member at low speed in either a clockwise or counter-clockwise direction, and a reversal of such rotation at high speed.

HENRY ,SPENCE. 

